This application discloses a reciprocating compressor including: a piston rod extending along a predetermined central axis that crosses an opening formed in an end of a cylinder, the piston rod being coupled to a piston and a crank mechanism to convey driving force from the crank mechanism to the piston; a rear head penetrated by the piston rod, the rear head closing the opening of the cylinder; and a rod ring portion configured to prevent a gas in the cylinder from leaking out from a gap between the rear head and the piston rod. The piston rod includes an outer circumferential surface on which an annular groove portion surrounding the central axis of the piston rod is formed. The rod ring portion includes an inner circumferential portion inserted into the groove portion, and an outer circumferential portion in sliding contact with an inner circumferential surface of the rear head.

A diaphragm pump has: a housing; a piston; a shaft; a rolling diaphragm, which is configured so that a lid portion reciprocally moves integrally with the piston; a driving device, which can convert rotational movement of a motor section to linear movement, and output the linear movement from an output axle to the shaft; a guiding member; and a restricting mechanism. The guiding member is placed on another axial end side of an interior of the housing with respect to the piston, attached to the housing, and able to guide the shaft movably in the axial direction. The restricting member is disposed in the housing and between the guiding member and the shaft, and able to restrict rotation of the shaft about the axis while allowing reciprocal movement in the axial direction.

The present invention discloses a super-power five-cylinder plunger pump, including a power end assembly, a hydraulic end assembly and a reduction gearbox assembly. The power end assembly is designed as a segmented structure including a crankcase, a crosshead case and a spacer frame. One end of the crosshead case is connected to the crankcase, and the other end of the crosshead case is connected to the spacer frame. The hydraulic end assembly is disposed at an end of the spacer frame and is connected to the crankcase through bolts sequentially passing through the spacer frame and the crosshead case. The reduction gearbox assembly is connected to the crankcase. A crankshaft in the crankcase is forged from alloy steel and includes six axle journals and five bellcranks. One bellcrank is disposed between every two adjacent axle journals, and the distance between the center of rotation of the bellcrank and the center of rotation of the crankshaft is 110 to 160 mm. Beneficial Effects: The super-power five-cylinder plunger pump has a rated input power of 5000 hp to solve the problem that there is no existing plunger pump of a specification matching high-power electric motors in electric drive fracturing, and solve the conflict between the limited well-site conditions in the oil and gas fields and the need of multiple matched fracturing equipment.

A reciprocating pump includes a first manifold which includes a pump chamber, a second manifold which is connected to the first manifold, and a seal which is disposed inside the second manifold and comes into slidable contact with a plunger. A communication pipe which extends across an inside of the first manifold and an inside of the second manifold comes into contact with the seal. Additionally, the reciprocating pump includes a collar which is disposed inside the first manifold and comes into contact with the communication pipe through which the plunger is inserted. The collar, the communication pipe, and the seal are sandwiched between the inside of the first manifold and the inside of the second manifold.

A hand air pump inflating device includes a cylinder body, a tubular shaft and a tubular piston rod extending longitudinally, larger and smaller end caps respectively enclosing rear ends of the piston rod and the cylinder body, front and rear piston ring modules respectively enclosing a front end of the piston rod and a rear end of the tubular shaft, and a one-way check valve disposed between the rear end of the tubular shaft and the rear piston ring module. The piston rod is movable forward and rearward relative to the cylinder body and the tubular shaft for inflating an inflatable object.

A closure for the fluid end of a reciprocating pump which uses a closure plate or assembly that is secured in a slot formed in the fluid end body so that no retaining threads must be formed in the body.

A pumping device for processing a liquid comprises: a plurality of pistons, each of which is slidable along a movement direction in order to vary the volume of a corresponding chamber; a casing inside of which a driving device is housed for moving each piston of the plurality of pistons along the movement direction; a head inside of which the chambers are at least partially obtained; a plurality of suction valves, each one of which is associated with a chamber and is operable for enabling the liquid to enter the chamber; a plurality of delivery valves, each one of which is associated with a chamber and is operable for enabling the liquid to exit the chamber.

Each suction valve has an axis arranged transversely with respect to a further axis of the delivery valve associated with the same chamber. The pumping device further comprises an intermediate body interposed between the casing and the head. The intermediate body is provided with a guide device for guiding each piston along the movement direction.

A wear sleeve is removably mounted on a piston rod. The piston rod includes a piston cap, a piston rod body, and a piston head, with at least one of the piston cap and the piston head being removable from the piston rod body. The wear sleeve is disposed over the piston rod body and prevents the piston rod from contacting dynamic seals disposed within a pump. The wear sleeve is mechanically secured in a cylindrical recess on the piston rod between a cap shoulder of the piston cap and a head shoulder of the piston head.

A compressor of an embodiment includes: a piston that is housed in a case and moves back and forth in an axis direction inside the case; a main shaft that i) extends in the axis direction inside the case, and ii) guides the piston to move in the axis direction; and a drive that drives the piston to move along the axis direction. The piston includes: a main shaft bush through which the main shaft passes in the axis direction; and a compression board that has an outer diameter greater than an outer diameter of the main shaft bush, and that is fixed to an end portion of the main shaft bush on a side in the axis direction. Fluid inside the case is compressed, and then is ejected to an outside of the case. The drive is arranged between the compression board and an end portion of the case.

A roller bearing assembly for use in a fracking pump crank shaft includes an inner ring being positioned an outer ring and a plurality of rolling elements disposed therebetween. Each of the rolling elements have a bore extending therein. The roller bearing assembly includes a cage having an annular disc with pins extending axially inward therefrom and into the bore. The pins are positioned on the annular disc so that the rolling elements are spaced apart from one another with a gap extending continuously therebetween. The gap is of a predetermined magnitude to maximize the number of rolling elements that fit between the inner ring and the outer ring to maximize load carrying capacity of the roller bearing assembly.